Problem: Solve for $t$ : $\dfrac{17}{20}=t+\left(-\dfrac{13}{20}\right)$ $t =$
Solution: To isolate $t$, we subtract $-\dfrac{13}{20}$ from both sides. Remember: Subtracting is the same as adding the opposite. $\begin{aligned} \dfrac{17}{20}&=t+\left(-\dfrac{13}{20}\right) \\\\ \dfrac{17}{20}{-\left(-\dfrac{13}{20}\right)}&=t+\left(-\dfrac{13}{20}\right){-\left(-\dfrac{13}{20}\right)} \\\\ \dfrac{17}{20}{-\left(-\dfrac{13}{20}\right)}&=t \\\\ \dfrac{17}{20}{+\dfrac{13}{20}}&=t \end{aligned}$ Simplifying, we get: $t = \dfrac{3}{2}$